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Slub yarn is a popular yarn because of its distinctive appearance. In this paper, the simulation of the fiber arrangement in the slub strand is proposed. After twisting, the slub strand is converted into slub yarn. A cylinder with a large length–diameter ratio is used to simulate the fiber, and the random arrangement of the fibers forms the slub strand. Spring-damper-mass models are established to prevent cross-embedding among fibers and gather fibers along the slub strand axis. The slub strand is twisted by the roller-collet twisting model in ABAQUS software. By comparing the twisting effect, it can be seen that the twist distribution of the slub yarn simulated by the finite element method is consistent with the real slub yarn spun on a ring-spinning frame. The work can predict the twist change of slub yarn by the established model. The established model provides the basis for future research work on the properties of slub yarn.

This paper focuses on the northwest region, which is related to China’s overall ecological security and ethnic stability. This paper selects the neighboring regions of Dingxi City, Gannan Tibetan Autonomous Prefecture and Linxia Hui Autonomous Prefecture as the starting point, deeply and systematically analyzes the impact of different lifestyles on the environment. Using environmental economics, ecological economics, environmental sociology and other related theories, ecological footprint were used to investigate different lifestyles’ impact to environment. Neural network were also used to carry out multi-perspective environmental impact research from the spatial scale and time scale. The research finds that Dingxi, Gannan and Linxia’s different mode of production has led to different lifestyle, and results in different impact on environment. The governments of the three places should take actions to promote ecological civilization and encourage the establishment of an ecologically-friendly and environmentally-friendly way of life so as to reduce the impact on the ecological environment and realize regional sustainable development.

Low temperature is an important environmental factor limiting the widespread planting of tropical and subtropical crops. The application of plant regulator coronatine, which is an analog of Jasmonic acid (JA), is an effective approach to enhancing crop’s resistance to chilling stress and other abiotic stresses. However, the function and mechanism of coronatine in promoting chilling resistance of tomato is unknown. In this study, coronatine treatment was demonstrated to significantly increase tomato chilling tolerance. Coronatine increases H3K4me3 modifications to make greater chromatin accessibility in multiple chilling-activated genes. Corresponding to that, the expression of CBFs, other chilling-responsive transcription factor (TF) genes, and JA-responsive genes is significantly induced by coronatine to trigger an extensive transcriptional reprogramming, thus resulting in a comprehensive chilling adaptation. These results indicate that coronatine enhances the chilling tolerance of tomato plants by inducing epigenetic adaptations and transcriptional reprogramming.

Exposure to cold triggers a spike in cytosolic calcium (Ca 2+ ) that often leads to transcriptional reprogramming in plants. However, how this Ca 2+ signal is perceived and relayed to the downstream cold signaling pathway remains unknown. Here, we show that the CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28) initiates a phosphorylation cascade to specify transcriptional reprogramming downstream of cold-induced Ca 2+ signal. Plasma membrane (PM)–localized CPK28 is activated rapidly upon cold shock within 10 seconds in a Ca 2+ -dependent manner. CPK28 then phosphorylates and promotes the nuclear translocation of NIN-LIKE PROTEIN 7 (NLP7), a transcription factor that specifies the transcriptional reprogramming of cold-responsive gene sets in response to Ca 2+ , thereby positively regulating plant response to cold stress. This study elucidates a previously unidentified mechanism by which the CPK28-NLP7 regulatory module integrates cold-evoked Ca 2+ signal and transcriptome and thus uncovers a key strategy for the rapid perception and transduction of cold signals from the PM to the nucleus.

Exposure to cold triggers a spike in cytosolic calcium (Ca

In this paper, the research on the transitional segment of slub yarn mainly focuses on the length of the transitional segment. Slub yarn was simulated by randomly determining the fiber position with the Monte Carlo method according to the draft principle of ring spinning for slub yarn. The length of the transitional segment was obtained by determining its starting and ending position according to the mass curves of the simulated and real-spun slub yarns. According to the data analysis, the fiber length, acceleration and deceleration time on draft rollers’ velocity, and slub multiple affect the length of the transitional segment. Both the lengths of the left and right transitional segments are all equal. The maximum error rate of the simulated value to the measured value of the length of the transitional segment is approximately 12%. The empirical formula has been established to estimate the length of the transitional segment. Compared with those of the simulated and real spun slub yarns, the error rate of the length of the transitional segment calculated by the empirical formula is less than 10%. The research content of this paper provides a basis for studying the appearance and properties of slub yarn.

The microstructure evolution and mechanical properties of the Mg-10Li-3Al-3Zn-0.25Si alloy undergoing multiple thermal cycles between high and low temperatures were explored in this study. The results showed that the thermal cycling process between high and low temperatures can lead to β-Li grain refinement and solid solution transformation of MgLiZn in the Mg-10Li-3Al-3Zn-0.25Si alloy. Furthermore, the strength of the Mg-10Li-3Al-3Zn-0.25Si alloy was reduced by 6–8%, while the elongation of the alloy was enhanced by approximately 65% after the thermal cycling process.

Generating video captioning automatically is an active and flouring research topic that involves the complex interactions between visual features and natural language generation. The attention mechanism obtains the key visual information corresponding to the word by removing redundant information. However, existing visual attention methods are indirectly guided by the hidden state of language model, ignoring the interactions between visual features obtained by attention mechanisms. Due to the existence of incomplete object or interference noise, attention mechanism with frame feature is hard to find correct regions-of-interest which closely related to the motion state. Worse still, at each time step, the hidden states have no access to the posterior decode states. The future predicted information is not fully utilized, which lead to the lack of detailed context-aware information. In this paper, we propose a novel video captioning framework with Memory-attended Semantic Context-aware Network (MaSCN) to capture the adjacent sequential dependency across multiple time stamps between different outputs for visual features. To exploit pivotal feature from coarse-grained to fine-grained, we introduce the attention module in MaSCN, which uses corresponding tailored Visual Semantic LSTM(VSLSTM) layers to more precisely map visual relationship information through multi-level attention mechanism. Besides, we integrate the visual features obtained through the attention mechanism as a late fusion. The visual semantic loss is used to explicitly memorize contextual information, capturing the fine-grained detailed cues. Compared with state-of-the-art approaches, the extensive experiments demonstrate the effectiveness of our method on MSVD and MSR-VTT datasets.

The popularization of smart phones has fostered the use of e-hailing apps, which can effectively reduce information asymmetry and provide ease and convenience during travel. Meanwhile, problems such as product homogeneity, slow operation speed, and interface confusion in travel apps also exist, leading to negative user experience. Building on the theory of planned behavior and technology acceptance model, this study examines multiple features of travel apps and their influence on university students’ experience and travel intentions. Findings of the study suggest that, compared to the contents of travel apps, the ease of use seems to have a stronger influence on students’ attitude, perceived behavioral control, and travel intention. The study contributes to the integration of the technology acceptance model and the theory of planned behavior in travel contexts. The findings also offer meaningful practical implications and recommendations on product and service design to relevant stakeholders willing to offer a better travel app user experience.

Nowadays, more and more places need authentication. Face recognition is a mature technology for identity verification research. Recognition accuracy is an important indicator for evaluating authentication algorithms. In order to improve the accuracy of identity verification, advanced face is used. Feature recognition algorithm is an effective way, but it is also an effective algorithm to study the factors affecting facial features. Therefore, many researchers study the recognition results based on the poses of the face, light and other factors. This paper is also a study on the factors affecting face recognition, mainly by studying the influence of the age and gender factors on the identity verification results, and using the deep learning method to classify facial features. The simulation results show that the average recognition rate reaches 83.73%. At the same time, this paper analyzes the effect of age and gender on the classification results. The results show that the recognition effect of middle-aged men in male subjects is lower than that of youth and the elderly. Women have little difference in recognition effect with age. Males have higher recognition rates than women.

Light and temperature are two key environmental factors that coordinately regulate plant growth and development. Although the mechanisms that integrate signaling mediated by cold and red light have been unraveled, the roles of the blue light photoreceptors cryptochromes in plant responses to cold remain unclear. In this study, we demonstrate that the CRYPTOCHROME2 (CRY2)-COP1-HY5-BBX7/8 module regulates blue light-dependent cold acclimation in Arabidopsis thaliana. We show that phosphorylated forms of CRY2 induced by blue light are stabilized by cold stress and that cold-stabilized CRY2 competes with the transcription factor HY5 to attenuate the HY5–COP1 interaction, thereby allowing HY5 to accumulate at cold temperatures. Furthermore, our data demonstrate that B-BOX DOMAIN PROTEIN7 (BBX7) and BBX8 function as direct HY5 targets that positively regulate freezing tolerance by modulating the expression of a set of cold-responsive genes, which mainly occurs independently of the C-repeat-binding factor pathway. Our study uncovers a mechanistic framework by which CRY2-mediated blue-light signaling enhances freezing tolerance, shedding light on the molecular mechanisms underlying the crosstalk between cold and light signaling pathways in plants.

Cold stress negatively affects maize (Zea mays L.) growth, development and yield. Metabolic adjustments contribute to the adaptation of maize under cold stress. We show here that the transcription factor INDUCER OF CBF EXPRESSION 1 (ZmICE1) plays a prominent role in reprogramming amino acid metabolome and COLD-RESPONSIVE (COR) genes during cold stress in maize. Derivatives of amino acids glutamate/asparagine (Glu/Asn) induce a burst of mitochondrial reactive oxygen species, which suppress the cold-mediated induction of DEHYDRATION RESPONSE ELEMENT-BINDING PROTEIN 1 (ZmDREB1) genes and impair cold tolerance. ZmICE1 blocks this negative regulation of cold tolerance by directly repressing the expression of the key Glu/Asn biosynthesis genes, ASPARAGINE SYNTHETASEs. Moreover, ZmICE1 directly regulates the expression of DREB1s. Natural variation at the ZmICE1 promoter determines the binding affinity of the transcriptional activator ZmMYB39, a positive regulator of cold tolerance in maize, resulting in different degrees of ZmICE1 transcription and cold tolerance across inbred lines. This study thus unravels a mechanism of cold tolerance in maize and provides potential targets for engineering cold-tolerant varieties.

The civil engineering supervision video provides the effective method to improve the quality of civil engineering supervision, but its usual retrieval by B+ tree can’t show the efficient performance to meet the real requirements. This paper uses some natural language processing ways, such as word embedding and combines semantic, to let the machine realize the content of supervision video and then focuses on the civil engineering supervision video retrieval annotated by supervision engineer. Firstly, we described the civil engineering supervision video hierarchical model with semantic, its framework and storage. And we proposed a CESVSR-tree data process algorithm to transform the civil engineering supervision video annotation into word vector through Chinese Wikipedia Entries and civil engineering entries, get the word weight value of each word. Secondly further research on video data index, we proposed the spectral clustering-based node split algorithm, it combines the traditional R-tree node splitting algorithm with spectral clustering algorithm, which improves the indexing speed of high-dimensional data such as video and word vector. Finally, in view of the rapid development of solid-state driver, this paper optimized the R-tree with the characteristics of solid-state driver, to improve the index construction speed on the hybrid storage structure.

In the civil engineering supervision, the management processes about personnel, materials, quality, safety, schedule and etc. are complex, which include large amount of data, involve more participants, and timely coordination and feedback is difficult. In this paper, we propose the data integration idea based on data-driven, which could guide the whole life cycle of civil engineering supervision from the top-level data organization, supervision of business processes, the interactive units and the users, the four-elements method TDTM and so on. Then, the data integration algorithms of civil engineering supervision are put forward to integrate the civil engineering supervision data from outside to inside and from coarse-grained to fine-grained, eliminate contradictions and redundancy and ensure data consistency. Finally, the civil engineering supervision data entities are determined, and we further analyze and discuss its query and report, data maintenance and conversion, and compare the functions in the different supervision platform. The civil engineering supervision unified data platform proposed could maintain the independence of the data, have the good scalability and support the more functions.

Great improvement has been made in the optimization on the near-field thermophotovoltaic system at the steady state, whereas system safety evaluation under near-field thermal radiation and transient output performance considering the energy consumption of the cooling device are lacking. Therefore, it is important to extend the investigation on the system to the transient state. Based on the law of energy conservation and theory of near-field radiative heat transfer, a transient energy transfer model of a W nanowire-based near-field TPV system considering the energy consumption of the cooling device was established. The heating process of each component in the system was explored, and the effects of the input power density and cooling medium’s velocity on system performances were analyzed. Moreover, a new evaluation index named the start-up power consumption was proposed to characterize the start-up performance of the system. The results show that based on the common working conditions, the maximum heating rate of the emitter in the transient process is up to 1500 K/s, which makes a serious threat to the experimental safety of the system. However, only the maximal operating temperature of 1752 K can be obtained according to the steady-state model and this temperature is within safe range, indicating the shortcomings of the steady-state model. The maximum heating rate of the emitter can be reduced to 304 K/s by adopting a progressive heating mode with a power supply rate of 20 W/cm2/s, showing that the safety operation of the system can be ensured. The highest cell efficiency occurs at the transient moment due to the increasing cell temperature. Increasing the cooling medium’s velocity is expected to maintain the highest cell efficiency until the steady state to improve the net system efficiency. However, the system needs external energy in the start-up stage because the cell is insufficient to produce enough electricity to drive the cooling device during this time, and the start-up power consumption of the system increases sharply with the increasing velocity of the cooling medium, which can be as high as 23405.9 W/m2. By comprehensively considering the net system efficiency and start-up power consumption, the alternative velocity was determined as 4 m/s. It can be seen that the transient energy transfer model of the near-field TPV system can be used to better guide the experimental safety design and comprehensively evaluate the system performance compared with the steady-state model.

γ-TiAl alloys are excellent candidate materials for high-temperature applications, although poor hot workability limits their widespread application. In the present study, the microstructure, mechanical properties and hot workability of TiAl-Nb-Mo alloy in the as-cast and as-extruded conditions were investigated. The as-cast TiAl alloy consisted of γ/α 2 lamellae, γ and β phase distributed at colony boundaries and on the lamellar interfaces. The tiny particles of ω 0 phase were formed, transformed from β phase during HIP treatment, which dissolved after hot extrusion. The TiAl alloy exhibited improved mechanical properties and excellent hot workability after hot extrusion because of grain refinement, the introduction of β phase and the disappearance of ω 0 phase. The anomalous yield stress phenomenon occurring in as-cast material disappeared in the as-extruded condition, which was ascribed to grain refinement that reduced the resistance of grain boundaries to intragranular slip at elevated temperature. The findings demonstrate the benefits of introducing small amounts of β phase to improve hot workability of TiAl-Nb-Mo alloys, particularly when followed by heat treatment to eliminate the β phase and increase the mechanical properties.

An experimental study and theoretical analysis of heat transfer performance of a sintered heat pipe radiator that implemented in a 50 L domestic semiconductor refrigerator have been conducted to examine the effect of inclination angle, combined with a minimum entropy generation analysis. The experiment results suggest that inclination angle has influences on both the evaporator and condenser section, and the performance of the heat pipe radiator is more sensitive to the inclination change in negative inclined than in positive inclined position. When the heat pipe radiator is in negative inclination angle position, large amplitude of variation on the thermal resistance of this heat pipe radiator is observed. As the thermal load is below 58.89 W, the influence of inclination angle on the overall thermal resistance is not that apparent as compared to the other three thermal loads. Thermal resistance of heat pipe radiator decreases by 82.86 % in inclination of 60° at the set of 138.46 W, compared to horizontal position. Based on the analysis results in this paper, in order to achieve a better heat transfer performance of the heat pipe radiator, it is recommended that the heat pipe radiator be mounted in positive inclination angle positions (30°–90°), where the condenser is above the evaporator.

The distributions of near-surface meteorological elements, such as wind, are greatly affected by the terrain underneath, which makes the power structure of micro geomorphic area more vulnerable to the influence of local climate. Single hills with length are one of typical terrains in microrelief. In this paper, the circulation caused by buoyant flows and temperate within typical single hilly terrain with length is studied. The Detached Eddy Simulation (DES) is used to integrate buoyancy, turbulence and micro-terrain into a single model and it is applied to the special situation of micro-terrain climate. How the wind field is influ-enced by different surface temperature and the model surface roughness is carefully described. The results show that, different surface temperature has a very strong effect on the speedup ratio. Compared with the air temperature, the lower the terrain surface temperature is, the more obvious the speedup ratio effect is, and vice versa. For different roughness surface terrain, the speedup ratio has almost the same characteristics.

In this article, the dynamics of colliding particles immersed in a viscous fluid is numerically investigated. An improved fictitious domain (FD) method for a solid–fluid system is developed and a collision strategy for multiple particles is presented. In earlier methods, a repulsive force is applied to the particles when their separation distance is less than a critical value and depending on the magnitude of this artificial repulsive force, collision of two or more particles may bounce unrealistically. In the present method, when the collision of two or more particles happens, the collision force acting on each colliding particle is determined by using the Discrete Element Method (DEM). Furthermore, the improved FD method employs a discrete δ -function in the form of bi-function to transfer quantities between the Eulerian and Lagrangian nodes similar to the immersed boundary method. This feature avoids the need to use Lagrange multipliers for imposition of the rigid body motion. Numerical results for motions of one or several particles in a viscous fluid are presented.

The mechanisms behind the repairing effects of the cotransplantation of olfactory ensheathing cells (OECs) with bone marrow mesenchymal stromal cells (BMSCs) have not been fully understood. Therefore, we investigated the effects of the cotransplantation of OECs with BMSCs on antiapoptotic effects in adult rats for which the models of SCI are induced. We examined the changes in body weight, histopathological changes, apoptosis, and the expressions of apoptosis-related proteins after 14 days and 28 days after transplantation. We also assessed animal locomotion using BBB test. We found that treatment with OECs and BMSCs had a remissive effect on behavioral outcome and histopathological changes induced SCI. Furthermore, we observed the significant antiapoptotic effect on cotransplant treated group. In addition, cotransplantation of OECs with BMSCs was found to have more significant repairing effect than that of OECs or BMSCs alone. Furthermore, the recovery of hind limb could be related to antiapoptotic effect of OECs and BMSCs through downregulating the apoptotic pathways. Finally, our data suggested the cotransplantation of OECs with BMSCs holds promise for a potential cure after SCI through the ability to incorporate into the spinal cord.

The entropic lattice Boltzmann method (ELBM) is an excellent method of numerical stability among of different versions of the lattice Boltzmann method for the simulation of hydrodynamics, especially for wind field simulation application of power grid disaster conditions. In this paper, an efficient improved particle swarm optimization (PSO) algorithm is studied for optimizing calculation parameters to achieve load balancing of ELBM on nonuniform grids in a heterogeneous computing platform. We also introduce a new concept of multi-block ELBM on composite grids for realization of the ELBM simulations of incompressible driven cavity flow. These new approaches rely on a two-dimensional space-time interpolation and solving the relaxation time parameter by direct approximation optimization strategy to guarantee conservation. Our CPU–GPU implementation of multi-block ELBM based on the improved PSO algorithm not only exploits adequately multi-core CPU computing resources for load balancing, but also follows carefully optimized storage to increase coalesced access on a GPU platform. The three-dimensional-driven cavity flow simulations validate the proposed multi-block ELBM even with severely under-resolved grids. In addition, some performance metrics are investigated based on the implementations of different refined grids and threading blocks. These results exhibit the improved PSO algorithm of the ELBM method which can optimize computing resource parameters in heterogeneous platforms, and the present multi-block ELBM can substantially improve the accuracy and computational efficiency for viscous flow computations.

In response to national policy for energy conservation and emissions reduction which require the appearance of new type of fly ash brick molding machine. Hence, it's exigent to explore substitute for the early brick machine. New type of fly ash brick molding machine is an automatic machine which is used to produce high density bricks with coal ash. It is good for energy saving and environmental protection. In this paper, the system working principle and key points hydraulic systems of the hydraulic brick machine are analyzed, the detail introduction is done for the system validation and verification method. After a certain time of testing and application, the system works well and reliably. Therefore, it has the user's high praises and also has been put into the mass production.

Osteosarcoma is the most common primary bone cancer which is associated with early metastatic potential and poor prognosis. However, the molecular mechanisms underlying osteosarcoma progression are not well characterized. Here, we investigated the role of miR-409-3p in osteosarcoma metastasis. Osteosarcoma tissue showed decreased expression of miR-409-3p compared to adjacent non-tumorous tissue. The expression level of miR-409-3p was negatively correlated with osteosarcoma metastasis. Overexpression of miR-409-3p in osteosarcoma cells (U2OS) inhibited cell migration and invasion. Bioinformatics analysis showed that catenin-δ1 (CTNND1, p120-catenin) is a direct target of miR-409-3p. Overexpression of miR-409-3p repressed the expression of catenin-δ1 in U2OS cells at both mRNA and protein levels. Meanwhile, miR-409-3p repressed the activity of luciferase reporter containing the 3'-untranslated region (3'UTR) of CTNND1 gene. Furthermore, expression of catenin-δ1 rescued the inhibitory effect of miR-409-3p on cell migration and invasion. Altogether, these results indicated that miR-409-3p targets catenin-δ1 to repress osteosarcoma metastasis.

This paper is concerned with the error behaviour of linear multistep methods applied to singularly perturbed Volterra delay-integro-differential equations. We derive global error estimates of A(@a)-stable linear multistep methods with convergent quadrature rule. Numerical experiments confirm our theoretical analysis.

In this article, the dynamics of particle-particle collisions in a viscous fluid is numerically investigated. An improved fictitious domain–based computational method for a solid-fluid system is developed and a collision strategy for multiple particles is presented. In earlier methods, a repulsive force is applied to the particles when their separation is less than a critical value and depending on the magnitude of this repulsive force, collision of two or more particles may bounce unrealistically. In the present method, when the collision of two or more particles happens, a direct force is added to each particle through Discrete Element Method (DEM) for particle collision. At the same time, a direct-forcing domain method, which is development of the fictitious domain(FD) method, is applied for simulation of multi-particle fluid flows. It employs a discrete δ- function in the form of bi-function to transfer quantities between the Eulerian and Lagrangian nodes as in the immersed boundary method. This method avoids the need to use Lagrange multipliers for imposition of the rigid body motion. Results for motions of several particles in a viscous fluid are presented.

Most analytical studies published on gas seals assume that grooved rings remain stationary while plain face rings rotate, regardless of which ring actually rotates. Indeed, examination of the simplified equations for thin fluid films reveals no difference whether the ring with the hydrodynamic lift features rotates or the plain face ring rotates, so long as rotation occurs in the proper direction for positive pressure and film stiffness generation. Suggestions have been made that differences exist between the two scenarios, especially when considering flow patterns and inertial effects of working fluid within the gas film and face grooves. In the present study, Computational Fluid Dynamics is used to examine these issues. Since the full Navier-Stokes equations are solved, simplifying assumptions become unnecessary. While the CFD results of the present study indicate the equivalency of the two rotational conditions, the details of the pressure development and velocity variations within the fluid film and f...

This paper presents an empirical approach for determining the effective lubricant rheological parameters in elastohydrodynamic contacts by using the experimental traction data taken from a conventional two-disc machine apparatus. These effective lubricant rheological parameters as functions of pressure and temperature are currently not available for most of the lubricants in practical applications, and are yet essential for traction calculations in elastohydrodynamic contacts. As a demonstration, comprehensive traction measurements are made with one gear lubricant for its effective rheological parameters. The lubricant parameters obtained are then incorporated into a traction model developed previously, and good agreement between model prediction and experimental observation is shown.

In gear applications where precipitous tooth failure mode such as scoring or scuffing has been avoided, “normal” wear becomes a life-determining factor. In this paper, sliding wear in spur gears, including the considerations of gear dynamics and rough-elastohydrodynamic lubrication, is analyzed. Formulas for equivalent wear rate and tooth wear profile along the line of action are derived. Results show that most materials are removed from both the addendum and dedendum tooth surfaces, and that the highest wear occurs at the beginning of an engagement. This high wear region corresponds to the root of the driving (pinion) teeth and the tip of the driven (gear) teeth. These analytical results correlate well with the practical evidences in AGMA documentation.

A sliding wear model has been developed for partial-EHL contacts, in which both the thermal desorption wear mechanism at low asperity contact temperature and the oxidative wear mechanism at elevated asperity contact temperature are considered. To include micro-EHL effects, digitized actual surface roughness profiles are used in simulating two contacting rough surfaces, and in obtaining the asperity contact area and asperity contact temperature distributions within a Hertzian contact region. Wear measurements in a two-disk machine configuration have been made over a comprehensive range of slide-to-roll ratios. The experimental results show a continuous decrease in wear rate with the increase in slide-to-roll ratio when the slide-to-roll ratio is relatively small, and a drastic rise in wear rate when slide-to-roll ratio is further increased. The experimental wear rate curve as a function of slide-to-roll ratio verifies the model prediction. The drastic rise in wear rate with the increase in slide-to-roll ratio in the range of slide-to-roll ratio beyond unity seems to suggest that a transitional phenomenon exists in the relation between wear rate and slide-to-roll ratio.

The major power losses in spur gears due to sliding and rolling friction have been analyzed by applying a simplified analytical friction model in the partial-elastohydrodynamic contacts where the friction is affected by both asperity interactions and hydrodynamic effects. Results based on this friction model suggest that the variations in both surface roughness and coefficient of asperity friction alter the traction coefficient appreciably. Reduction of the traction coefficient can improve the efficiency of gears. Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988